to_xlsx for DataMapper

dm-to_xlsx.rb

# -*- encoding : utf-8 -*-

module DataMapper
  module Xlsx

    module Model

      def xlsx_columns
        self.properties.reject{ |p| p.options[:no_export] }.
            sort{ |a, b| (a.options[:export_pos] || 0) <=> (b.options[:export_pos] || 0) }.
            map(&:name)
      end

      def xlsx_human_attribute_name(field)
        if (field.to_s =~ /^([^\.]+)\.(.*)$/) && relationships[$1]
          "#{relationships[$1].target_model.model_name.human} - #{relationships[$1].target_model.xlsx_human_attribute_name($2)}"
        else
          human_attribute_name(field)
        end
      end

      DataMapper::Property.accept_options(:no_export, :export_pos)

      # Defaults
      DataMapper::Property::Serial.no_export(true)
      DataMapper::Property::Discriminator.no_export(true)

      DataMapper::Model.append_extensions(self)
    end

    module Collection

      def to_xlsx(options = {})
        row_style = options.delete(:style) || {:sz => 12, :border => { :style => :thin, :color => "00" }}
        header_style = options.delete(:header_style) || row_style.is_a?(Hash) ? row_style.merge(:alignment => {:horizontal => :center}, :b => true) : row_style
        types = Array(options.delete(:types))

        columns = options.delete(:columns) || self.model.xlsx_columns

        p = options.delete(:package) || Axlsx::Package.new

        row_style = p.workbook.styles.add_style(row_style) if row_style.is_a?(Hash)
        header_style = p.workbook.styles.add_style(header_style) if header_style.is_a?(Hash)

        sheet_name = options.delete(:name) || self.model.model_name.human(:count => 2)

        wb = p.workbook
        wb.add_worksheet(:name => sheet_name) do |sheet|

          sheet.add_row columns.map{ |c| self.model.xlsx_human_attribute_name(c) }, :style => header_style

          self.each do |obj|
            sheet.add_row(columns.map { |c|
                o = obj
                field = c.to_s
                while (field =~ /^([^\.]+)\.(.*)$/) && model.relationships[$1]
                  o =  o.send($1)
                  field = $2
                end
                o.send(field)
              }, :style => row_style, :types => types)
          end
        end

        p
      end

      DataMapper::Collection.send(:include, self)

    end

  end
end